Isometric strength, endurance, and the blood pressure and heart rate responses during isometric exercise in healthy men and women, with special reference to age and body fat content

1975 ◽  
Vol 360 (1) ◽  
pp. 49-61 ◽  
Author(s):  
Jerrold S. Petrofsky ◽  
Alexander R. Lind
2011 ◽  
Vol 5 ◽  
pp. NMI.S8567 ◽  
Author(s):  
Cameron G. McCarthy ◽  
Tyler M. Farney ◽  
Robert E. Canale ◽  
Rick J. Alleman ◽  
Richard J. Bloomer

Background Dietary supplements are often marketed to increase lipolysis and thermogenesis, with the proposed end result being weight loss and body fat reduction. It was the purpose of the present investigation to study the acute effects of a weight/fat loss supplement within a sample of healthy human subjects. Methods Twelve subjects (men 24.8 ± 4.3 yrs; women 22.8 ± 0.4 yrs) ingested a dietary supplement (OxyELITE Pro™) or a placebo, on two separate days in a double-blind, cross-over design. Blood samples were collected immediately before ingestion, and at 60 and 120 minutes post ingestion, and analyzed for plasma glycerol and free fatty acids (FFA). Breath samples were collected immediately before ingestion and at 30, 60, 90, and 120 minutes post ingestion, for a measure of kilocalorie expenditure using indirect calorimetry. Area under the curve (AUC) was calculated. Heart rate and blood pressure were recorded at all times and rate pressure product (RPP) was calculated. Results AUC was greater for supplement compared to placebo for glycerol (22.74 ± 1.98 μg · mL-1 · 2 hr-1 vs. 15.76 ± 1.36 μg · mL-1 · 2 hr-1; P = 0.001), FFA(1.62 ± 0.07 mmol · L-1 · 2 hr-1 vs. 0.78 ± 0.12 mmol · L-1 · 2 hr-1; P < 0.0001), and kilocalorie expenditure (149 ± 7 kcal · 2 hr-1 vs. 122 ± 8 kcal · 2 hr-1; P = 0.005). Heart rate ( P = 0.02), systolic blood pressure ( P < 0.0001), and RPP ( P = 0.002) were higher for supplement compared to placebo. Conclusion Ingestion of OxyELITE Pro™ resulted in an increase in blood markers of lipolysis, as well as metabolic rate, during a two-hour post ingestion time period. An increase in hemodynamic variables was also observed. These findings are in reference to a sample of healthy men and women who were naïve to treatment with the dietary supplement. Additional work is needed to determine if the acute changes observed here would persist with chronic use of the supplement and possibly lead to weight/body fat loss over time.


Metabolism ◽  
2002 ◽  
Vol 51 (4) ◽  
pp. 531-536 ◽  
Author(s):  
Bernd Fruehwald-Schultes ◽  
Kerstin M. Oltmanns ◽  
Barbara Toschek ◽  
Stefan Sopke ◽  
Werner Kern ◽  
...  

1997 ◽  
Vol 273 (3) ◽  
pp. E471 ◽  
Author(s):  
G Paolisso ◽  
D Manzella ◽  
N Ferrara ◽  
A Gambardella ◽  
P Abete ◽  
...  

Low-to-high frequency ratio (LF/HF) is an indirect index of sympathovagal balance derived by heart rate spectral analysis. We investigated the effect of glucose ingestion on LF/HF in 17 healthy, normotensive young subjects (9 male, 8 female) with a wide body fat content range (body fat = 29 +/- 5.9%; range = 19-42%) and a normal thyroid hormone status. Before and after an oral glucose tolerance test (OGTT), the Holter technique and indirect calorimetry allowed us to determine heart rate and substrate oxidation in all subjects. At baseline, LF/HF correlated with body fat (r = 0.60, P < 0.005), waist-to-hip ratio (r = 0.57, P < 0.01), fasting plasma insulin (r = 0.55, P < 0.04), leptin (r = 0.56, P < 0.01), and norepinephrine (r = 0.58, P < 0.009) concentrations. Age-, body fat-, content-, and fat-free mass-adjusted respiratory quotient (r = 0.59, P < 0.007) and basal metabolic rate (r = 0.61, P < 0.001) were also correlated with basal LF/HF. Along with OGTT plasma glucose, insulin and norepinephrine concentrations and basal LF/HF significantly rose at 60 min and then declined throughout the test. Area under the curve (AUC) for LF/HF correlated with body fat (r = -0.66, P < 0.004), fasting plasma leptin concentration (r = -0.57, P < 0.01), glucose induced thermogenesis (r = 0.62, P < 0.001), glucose uptake (r = 0.59, P < 0.007), and AUC for plasma norepinephrine concentration (r = 0.63, P < 0.001). Water instead of glucose ingestion does not significantly affect LF/HF (n = 8). In conclusion, our study supports the hypothesis that glucose ingestion affects LF/HF and that such change is related to the amount of body fat.


2017 ◽  
Vol 32 (6) ◽  
pp. 364-368 ◽  
Author(s):  
T. Jezdimirovic ◽  
S. Semeredi ◽  
V. Stajer ◽  
J. Calleja-Gonzalez ◽  
S.M. Ostojic

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